Mechanism for machining out-of-round piston-ring castings



C. E. JOHNSON MECHANISM FOR MACHINING OUT OF ROUND PISTON RING CASTINGS Filed Sept. 7. 1920 IJIIHH fiber/e5 [Lb/712500 Mechanism for Machining Out-of-R-ound Patentedfict. 16, 1-923.

y 1,411,030 'uurrau STATES PATENT OFFICE.

CHARLES E. JOHNSON, 0F MUSKEGON, MICHIGAN.

FOE MACHINING OUT-OF-ROUNDyPISTON-RING CASTINGS.

' Application filed September 7,1920. Serial No. 408,507.

To all whom it may concern Be it known that I, CHARLES E. JoHNsoN, a citizen of the United States of America, residing at Muskegon, in the county of Muskegon and State of Michigan, have invented certain new anduseful Improvements in Piston-Ring Castings; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to' which it appertains to make and 'use the same.

This invention relates to a novel mecha nism and apparatus 'for' machining piston ring castings. v

In the manufacture of .piston rin s it is the best practice to make an individual ring casting for each piston ring to be produced, the same being cast inwhat is known as out-of-round and not in true circular form, such that on removal of a gap piece at one side of the ring casting and bringing the ends at the parting thus made to.- gether a ring of true circular form is made.

Heretofore it has been usual to finish each end of the ring casting and rough grind its outer curved surface after which the gap piece was removed, the casting being afterward compressed into true circular form and the outer surface of the ring casting then finished, first by taking a roughing cut followed by a finishing cut which completed the ring. It is,of course, necessary that the casting be in practically true. circular form when the finishing at the outer curved surface is done in order to make rings of uniform thickness.

The present invention is directed to a mechanism by means of which the ring may be acted 'upon and partially finished at its outer curved surface prior to the removal of the gap ring; particularly t 1e rough cut at the outer curved surface of the ring casting may be done before the ring casting is parted at one side. From this an elimination of the necessity of testing each casting for thickness after it has been rough ground follows. My invention is directed to a relatively simple mechanism by means of which the individual ring casting may be. distorted from its normal out-of-round form, held to a substantially true circular fQlfm,"T O'. tated while so held and machined at its outer curved surfaces while thus heldiece at one side of the rotated. The invention comprises many novel features of construction and details of mechanism for accomplishing this end as Wlll appear fully and in detail from the following description taken in connection with the accompanying drawings, in which;

Fig. 1 is a front elevation of 'a lathe equipped with my invention. 1

. Fig. 2 is a plan view of the tail stock portion of the lathe.

Fig. 3 is acentral vertical section taken through a head which is connected to the head stock spindle of the lathe.

Fig. 4 is a similar section taken through the head used with and connected to the tail stock spindle.

Fig. 5 is an end elevation of the head shown in Fig.3, and

Fig. 6 is a similar end elevation of the head shown in Fig. 5.

Like reference characters refer to like parts in the different views .of the drawing.

The lathe has the usual bed 1, head and tail stocks 2 and 3 and the common and well known tool support indicated at 4. The tail stock spindle 5 is of the quick action type being slidably mounted-through the tailstock and operated by a link 6 pivotally connected at one end thereto, its opposite end having connection to an operating handle 7 which is pivotally mounted on and above the tail stock. By this construction the spindle 5 may be moved quickly back i and forth.

On the head stock spindle 8 of the lathe a head is adapted to be detachably connected, the same consisting of a cylinder 9 interiorly bored and. threaded as indicated at 10 so that it may be screwed on the end of the head stock spindle. The head 9 is provid'ed with a central reduced extension 11 over which a collar 12 is placed, the

same being connected with the head 9 so outer'side whereby a securing nut 17 may be threaded-onto the end of the projection llaud lie flush with the outer side of the collar, any suitable spanner wrench being used for operating the nut, the nut being 1n front of which extends a cylindrical pro jection 21, the diameter of which is between that of the flange 20 and the spindle 5*. Over projection 21' two disks 22 and 23 are placed between which a successive series of balls 24 are located, the same traveling in suitable races made inthe adjacent faces of the disks. A member 25 is likewise placed over the end of -.the projection 21 it being formed with an integral sleeve portion 26 to enclose disks 23 and 24 and the balls be- 7 tween the same and protect the bearings against the entrance of dust or other undesirable foreign substances The member 25 is formed with a, recess in its outerportion which leaves an annular. lip 27. around the end of the extension 21 and the parts are connected together by a head 28 which is detachably connected to and lies against the end of the projections 21 and one lip 27, any suitable means of connection, such as a screw indicated in-dotted lines in Fig.

i 4, being used. This head 28 is located in the recess made in the member 25.

A hardened disk or plate 29 havin the same diameter as the collar 12 is p aced against the member 25 and secured thereto by a lurality of screws 30. A pin 31 of a size adapted to freely enter any ofthe openings 19 projects in front of the face of disk 29.

In operation an out-of-round ring casting of a size to pass over and against the conical surface 15 is placed against said surface,handle7then grasped and the head on the tail stock spindle moved to the opposite side of the ring casting and pressed firmly against the same. When this is done the ring casting is sprung from its out-ofround form and shaped to fit the conical surface 15 thereby distorting the casting to a circular form. The pin 31 enters one of the openings 19 and it is apparent that with the rotation of the head 9 and attached parts the plate 29,. member 25 and disk 23 turn freel about the cylindrical projection 21, the isk 23 riding freely on the balls 24. The ring held between the heads also turns with them. The outer face of the plate 29 is held at. all times in the same plane perpendicular to the axis of the head stock spindle. This insures that the pressure "exerted on a ring castingcast normally outof-round will cause it, when brought against the conical surface 15 of collar 12, to assume .a circular form, whereupon a tool carried by the tool holder 4 of the lathe may be fed lengthwise of the ring casting and a cut taken therefrom. This cut, the first roughing cut taken from the casting removes the outer scale from the casting and also any irregularities and extra thicknesses of metal,

leaving the ring casting in shape such'that after thepartinghas been made in a side thereof only one more operation is needed, that being a finishing 'cut' of a very small amount. As soon as thetool has finisheda cut on the ring. casting the handle 7 is grasped and the spindle 5 removed in the opposite direction, this releasing the ring and permitting it to assume its normal out-of-round form. The ring drops from the end of the collar 12 into any suitable receptacle placed to receive it.-

This construction of mechanism for machining out-of-round ring castings is relatively simple and with it the castings may be machined very rapidly. In fact the feed of the cutting tool may be automatic and all thatthe operator has to ,do is to press the rings against the conical surface 15 and perate the handle 7 for the holding and releasing of the castings. The advantages whicharise and the steps saved in finishing piston rings are fully outlined in my application on. the method of machining piston ring castings, the method not being limited to any one particular construction of ma-.

chine and being the subject matter of a 00- pending application.

The appended claims define the invention and Iconsider myself entitled to all modifications which fall within their scope. I claim:

1. -A mechanism of the character described, a spindle mounted for rotation, .21 head secured to said spindle and provided with an annular conical'surface at its free end against which one side of an out-of-round piston ring casting is adapted to be placed, a second spindle'in alignment with the first spindle, a second head mountedon said second spindle including apart adapted to turn about the longitudinal axis of the spindle, said second head having a face disposed in a'plane perpendicular to the axis of the spindle, means for moving said second spindle and attached head so as to bring said face of-the headagainst the opposite side of the ring casting, and means for connecting the heads together when said second head is moved toward the first head,

substantially as described.

2. In combination, a rotatably mounted spindle, a head thereon formed at its free end with an annular conical surface against I it which one side of an out-of-round piston ring casting is adapted to be placed, asecond head mounted a short distance fromthe first head means for moving one of said heads toward the other head to clamp'the ring casting between the heads and force the casting against said conical surface whereby said ring casting is sprung to circular form and firmly held between the heads to rotate therewith, substantially as described.

3. In a mechanism of the character described, a rotatably mounted spindle, a head secured thereon and provided with an annular conical surface at its free end against which one side of an out-of-round piston ring casting may be placed, a second spindle slidably mounted in alinement. with the first spindle, a second head rotatably mounted on the inner end of said second spindle and formed withra face adapted to come against the opposite side of the piston=ring casting and thereby force the ring casting against said conical surface and distort it to circular form, and means for connecting the heads together when the second spindle is moved to bring its head toward the first head to clamp said ring casting between them, substantially as described.

p 4. In combination, a rotatably mounted spindle, a head thereon provided at its free end with an annular conical surface and with a plurality of openings located in a circle inthe free end of the head, a second spindle slidably mounted in alinement with the first spindle, a second head rotatably .said second head and adapted to enter any one of said openings in the first head to connect the heads together for rotation, substantially as and for the purposes described.

5. In combination, a lathe provided with head and tail stocks, a spindle rotatably mounted on the head stock, a spindle slidably mounted through the tail stock in alinement with the head stock spindle, a head formed with an annular conical surface at its free end secured to the head stock spindle, a second head rotatably mounted on the-inner end of the tail stock' spindle, said second head including a face plate having an outer face lying in a plane perpendicular to the axis of the spinc les, and means for instantaneously connecting the heads to-- gether when the tail stock spindle is moved to bring its head to the head on the head stock spindle, substantially as described.

In testimony whereof I afiix myrlsi nature.

CHARLES E. JO SON. 

